The present invention relates to a fuse holder for a high-voltage system, in particular for a high-voltage battery system of an electric drive, and primarily to a fuse holder for accommodating an electric fuse link, and to a method for inserting or removing a fuse link.
Among the ways in which the automotive industry is reducing the use of fossil fuels is gradual electrification of vehicle drives of hybrid and electric vehicles. In addition, auxiliary and ancillary units in such vehicles are increasingly being electrified, e.g. electric power steering systems. In order to provide the power required in hybrid and electric vehicles, high-voltage battery systems in the form of chargeable or rechargeable energy accumulators are being used. High-voltage battery systems include nickel-metal hydride, lithium-ion and sodium-nickel chloride battery systems, for example. Lithium-ion batteries are being used more and more often since they are distinguished by relatively high energy densities and cell voltages.
For the use of lithium-ion cells in battery systems for the automotive sector, a multiplicity of cells are generally interconnected in series, in parallel or in parallel and in series to form modules, and a number of modules are combined to form battery blocks. In electric vehicles, such battery systems in some cases have voltages of over 450 V, and, even in the case of hybrid vehicles, the voltage of 60 V assumed as the safety threshold for contact with humans is exceeded. When such battery systems are used as primary sources of energy, a relatively high current can furthermore occur. To separate a high-voltage battery system from a consuming system, e.g. an electric drive of a vehicle, on one side or on both sides, high-voltage battery systems can be provided with isolating devices, which have high-voltage fuses, high-voltage contactors and service disconnectors, for example. In normal operation and during servicing/maintenance but also in accidents or when there is a fault in the system, galvanic isolation and contact protection from dangerous potentials are possible with the aid of these isolating devices (operator protection).
The high voltages and currents which occur in high-voltage battery systems are typically protected by a fuse in the circuit to avoid damage in the event of a fault. If there is a fault, there may be voltage across the contacts of the fuse when installing the fuse or when repair work is necessary, owing to the battery forming the primary energy source. Due to carelessness or incorrect working methods, short circuits may occur, and these can cause damage to battery cells, electronic components, electrical components and mechanical components. There is furthermore the risk that a technician may accidentally touch live components during a repair and may be put at risk by an electric shock.
Fuses or fuse links are generally accommodated by a fuse holder and inserted between a voltage source, e.g. a high-voltage battery, and an electric drive. Fuse boxes or cases are known from the publications DE 103 30 565 B4, DE 196 15 561 C2 and DE 600 08 347 T2, for example, and typically have a top and a bottom housing part, wherein the top housing part can be designed as a cover. The fuse links are arranged and secured in a receiving region, into which also a busbar can project. The fuse boxes or cases can generally be secured on the battery. While the fuse boxes or cases known from the prior art are intended to protect one or more fuse links from external influences (mechanical influences, heat), make it easier to exchange fuse links and reduce fixing and fastening errors, unintentional contact between the fuse link and the battery casing when exchanging the fuse link, and hence a short circuit, cannot be completely excluded.
Given this background situation, it is an object of the present invention to make available a holding device for accommodating a fuse link which allows reliable and simple insertion or removal of the fuse link, thus making it possible to exclude a short circuit with a tool or between the fuse link to be inserted or removed and the housing of a battery system and hence also the risk of injury to people from an electric shock.